The Legislature IX of Italy was the 9th legislature of the Italian Republic, and lasted from 12 July 1983 until 1 July 1987. Its composition was the one resulting from the general election of 26 and 27 June 1983. The election was called by President Sandro Pertini one year before the previous legislature's natural end on 5 May 1983, after a crisis in the incumbent government majority (Pentapartito).

The 1983 Italian general election was held in Italy on 26 June 1983. The Pentapartito formula, the governative alliance between five centrist parties, caused unexpected problems to Christian Democracy. The alliance was fixed and universal, extended both to the national government and to the local administrations. Considering that the election result did no longer depend on the strength of the DC, but the strength of the entire Pentapartito, centrist electors began to look at the Christian Democratic vote as not necessary to prevent a Communist success. Moreover, voting for one of the four minor parties of the alliance was seen as a form of moderate protest against the government without giving advantages to the PCI. Other minor effects of this election were a reduction of the referendarian Radical Party and the appearance of some regional forces.